The United States, South Korea and Japan held a joint naval missile defence exercise today to counter North Korea's evolving nuclear and missile threats.<br />''<br />''North Korea launched an intercontinental ballistic missile (ICBM) on Wednesday, said South Korea's navy.<br />''<br />''North Korea fired its latest Hwasong-18 missile, which it describes as the core of its nuclear strike force, off the east coast.<br />''<br />''The Navy further said that today's trilateral drill was conducted in international waters between South Korea and Japan, bringing together destroyers equipped with Aegis radar systems from the three countries.<br />''<br />''The North's ICBM launch was condemned by the U.S., South Korea and Japan, though Pyongyang rejected the condemnation, saying it was an exercise of its right to self-defence.<br />